If not the fiberglass take down units. All you need is Aluminum tubing. We replaced ours from tubing at the local recycle place. Take the ends that go in to the eyelets cutting them approx 4" from the top inserting that tent end in to the new tubing. You can secure the 2 pcs with an Al river, or sheet metal screw.

Something like this only in 1/2" dia. But you may need 3/4" o.d depending what dia poles you have now.
http://www.lowes.com/pd_216096-37672...luminum+tubing